When operating a motor vehicle, a driver must be notified of all conditions which might jeopardize safety or affect proper operation of the vehicle. For examples, an ajar door or engine malfunction is commonly detected by a built-in sensor and the status of that condition announced by a dashboard light, message, chime, or sometimes a verbal recorded message. Upon notification, a driver can then take corrective action.
In the case of motor vehicles, there have been various proposals put forward to enhance driver focus to the detection of an emergency condition. Such proposals have included the incorporation of vibrating units mounted within a steering wheel which generate mechanical vibrations perceivable by touch and ear of the driver.
In airplanes, a device called a “shaker stick” is used to alert the pilot to an emergency, such as an impending stall. A particular disadvantage of these prior art systems for motor vehicles resides in the fact that the mechanical vibrations generated in the steering wheel are often indistinguishable from normally occurring vibrations in non-emergency situations. For example, an out of balance tire or rough road can result in perceived vibrations in the steering wheel which are indistinguishable from those created by the prior art vibrating units.
Accordingly, there exists a need for a vehicular steering system which will help focus driver attention to an emergency condition, and can be readily distinguished from normal occurring operating conditions, such as road vibrations.